Electrical contact block



March 1961 R. c. MARTIN 2,975,393

ELECTRICAL CONTACT BLOCK Filed Oct. 6, 1958 71F- 9\ ,e M 1,6 4 X o [7 I I 1 g I? i z United States Patent ELECTRICAL CONTACT BLOCK Ray C. Martin, RR. 1, Hamilton, N. Dak.

Filed Oct. 6, 1958, Ser. No. 765,636

1 Claim. (Cl. 339-184) My invention relates to new and useful improvements in electrical contact blocks, more particularly, for electrical blocks having three connections, one of which is a ground. The conventional contact block or plug designed for three pronged connections is extremely difiicult to engage and disengage, particularly those contact blocks which are designed to carry relatively heavy current for electrical arc welding or the like. The male and female contacts of such blocks are manufactured with relatively close tolerances so that a tight fit is ensured in order to prevent areas of high resistance occurring and possible arcing.

The manipulation of such blocks is particularly difficult when they are situated on the exterior of a build ing, such as a farm building for example, particularly at night or in cold weather.

I have overcome these disadvantages by providing an electrical contact block having an extending handle portion for leverage purposes and having one of the contact blades hooked and adapted to engage a pin in the female portion thus enabling a cam action to be exerted when engaging or disengaging one from the other, thus facilitating such action.

The principal object and essence of my invention is, therefore, to provide an electrical block of the character herewithin described which permits one of the contact blades to be engaged with a hooking action to the corresponding blade receiver, whereupon leverage may be applied to engage the remainder of the contact.

Another object of my invention is to provide a device of the character herewithin described which includes an elongated handle on at least one of the portions, said handle facilitating the leverage action.

A yet further object of my invention is to provide a device of the character herewithin described which makes it virtually impossible to engage the contact blades within the wrong receivers.

A yet further object of my invention is to provide a device of the character herewithin described which is easily adaptable for use as a connection between adjacent lengths of electrical cable.

With the foregoing objects in view, and such other objects and advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, my invention consists essentially in the arrangement and construction of parts all as hereinafter more particularly described, reference being had to the accompanying drawings in which:

Figure 1 is a front elevation of my device sectioned in part substantially along the lines 11 of Figure 2.

Figure 2 is a side elevation of my device but sectioned to show the interior thereof.

Figure 3 is a side elevation of a modification of my device sectioned to show the interior thereof.

Figure 4 is a representation in reduced scale showing the male portion detached from the female portion, the female portion being sectioned.

In the drawings like characters of reference indicate corresponding parts in the different figures.

Proceeding, therefore, to describe my invention in detail, reference should first be made to Figures 1, 2 and 4, which show a male portion collectively designated 1 and a female portion collectively designated 2.

The portion 2 consists of a face block 3, having a base edge 4 and an opposite or upper edge 5. A rear cover 6 is detachably secured to the rear 7 of the face block by means of screws 8, and it will be noted that the face block is shouldered as at 9 to receive the cover. This cover defines an enclosure 10 to the rear of the face block, said cover being adapted to carry wires (not illustrated) through a wire clip 11 to the source of electrical energy.

This female portion is adapted to be secured to a wall or the like (not illustrated) by conventional means, and it is preferably manufactured from a reinforced plastic.

Embedded into the face block 3 are three contact blade receivers 12, 13 and 14 and it is desirable that these receivers be resilient to ensure good contact when the male and female portions are placed together. The open ends 15 of these contact blade receivers are substantially flush with the front surface 16 of the face block and contact lugs 17 are formed on the rear edges 18 of the receivers adapted to receive wires passing through clip 11.

It will be observed from Figure 1 that the receivers 12 and 13 are situated side by side and substantially adjacent the base edge 4 of the face block whereas the receiver 14 is situated between the receivers 12 and 13 but upwardly with regard to same or adjacent the upper or opposite edge 3 of the face block.

A pin 19 is situated transversely across the upper end of the receiver 14 and is embedded into the face block, the presence of which will hereinafter become apparent.

The male portion 1 also includes a face block identified by the reference character 20, said face block having a base edge 21 and an upper edge 22. This portion also has a configuration complementary to the configuration of the female portion 2, said configuration being best seen in the front elevation shown in Figure l.

A cover plate 23 is secured to the face block 20 by means of screws 24 and also defines an enclosure 25, the urpose of which is similar to the enclosure 10.

The face block 20 has formed integrally therewith. a handle 26 extending downwardly from the base edge 21, said handle preferably being provided with finger engaging grip 27. The handle is bored longitudinally as at 28 and a wire clip 29 is situated at the upper end of the bore where it enters the aforementioned enclosure 25.

From the foregoing it will be appreciated that an electrical cable can extend downwardly through the handle as illustrated by the reference character 30 in Figure l.

The face block 20 is provided with a plurality of contact blades 31, 32 and 33, which are secured to the face block and extend outwardly therefrom. The contact blades, which are arcuated when viewed in side eleva tion, also include wire connectors 34 on the rear edges thereof to which wires from electrical cable 30 may be secured as by nuts and bolts 35 (see Figure 1). The blades 31 and 32 are situated side by side and adjacent the lower or base edge 21 of the face block, whereas the contact blade 33 is situated between the blades 31 and 32 but upwardly therefrom or adjacent the upper or opposite edge 20 of the face block and it will be appreciated that the positioning of the blade contacts corresponds to the positioning of the contact receivers in the female portion 2.

The blade contact, specifically designated 33, has a hook 36 formed on the upper edge thereof, as clearly shown in Figures 2 and 4, and this hook is adapted to engage the aforementioned pin 19 when it is desired to engage the male portion 1 with the female portion 2.

In operation, when it is desired to connect the portion 1 to the portion 2, the hook 36 is engaged under the pin 19 by positioning the portion 1 as indicated in Figure 4, whereupon downward pressure upon the handle 26 in the direction of arrow 37, forces all of the blades into engagement with the blade receivers, the hook providing the necessary fulcrum and arcuate configuration of the blades giving a camming action which facilitates said engagement even under the most adverse conditions.

Disengagement of the portion '1 from the portion 2 is a reversal of this procedure, in other words, the handle is grasped and moved in the opposite direction to arrow 37, thus disengaging the blades from the receivers and permitting the operator to then disengage the hook 36 from the pin 19.

Figure 3 shows a modification of my device wherein it is used as a cable connector connecting two lengths of cable together.

The construction of the components is identical to that hereinbefore described, with the exception that the female portion 2 is also provided with a handle 38, extending from the face portion in a direction opposite to handle 26. This facilitates the connecting and disconnecting of the portions one with and from the other in a similar manner hereinbefore described.

Finally, I prefer that the male portion 1 be manufactured from a moulded rubber or the like for abrasion resistance purposes.

Since various modifications can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claim without departing from such spirit and scope, it is intended that ail matter contained in the accompanying specification shall be inter preted as illustrative only and not in a limiting sense.

What 1 claim as my invention is:

An electrical connector comprising in combination a female receptacle member and a male plug member,

said female receptacle member comprising a hollow body having a front wall provided with an opening, a pair of transversely spaced contact blade receivers provided in said body and a third contact blade receiver provided in the body between and vertically offset from said pair of receivers, said pair of receivers and said third receiver having an entrance through said opening, electrical conductors connected to said pair of receivers and to said third receiver, said third receiver including a pair of transversely spaced receiver elements and a pin extending transversely therethrough, said male plug member comprising a body having a wall in abutment with the front wall of the body of said female member when the male and female members are connected, a pair of transversely spaced contact blades and a third contact blade provided in the body of the male member and projecting through the said wall of the latter and through said entrance to engage, respectively, the said pair of blade receivers and the said third blade receiver of the female member, electrical conductors connected to said pair of blades and to said third blade, said third blade being disposed between and ofiset from said pair of blades and having an edge provided with a notch forming a hook portion at the said edge of the third blade, said hook portion being received between said pair of spaced elements of said third receiver and engaging said pin, said pin providing fulcrum means for said hook portion whereby said male and female members may be connected and disconnected by relative swinging thereof about said fulcrum means, and a handle provided on at least one of said members for swinging the same relative to the other member.

References Cited in the file of this patent UNITED STATES PATENTS 1,497,420 White June 10, 1924 1,629,568 Benjamin May 24, 1927 2,680,639 Vigmostad June 8, 1954 FOREIGN PATENTS 684,915 Great Britain Dec. 24, 1952 

